This application claims priority under 35 U.S.C. §119(a) of Korean Patent Application No. 2003-90035, filed on Dec. 11, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a method and apparatus for estimating the volume of toner consumption. More particularly, the present invention relates to a method and apparatus for accurately estimating the volume of toner consumption of an electrophotographic image forming device, such as a laser printer, by subtracting the volume of toner consumption corresponding to overlapping areas between adjacent dots.
2. Description of the Related Art
Generally, a laser printer projects a laser beam emitted by a laser diode onto a photosensitive drum in response to a video signal of an input image. Toner is attached to the surface of the photosensitive drum, and the attached toner is attached to a sheet of paper, thereby forming an image, such as a character or a picture.
FIG. 1 is a block diagram of a conventional apparatus 100 for estimating the volume of toner consumption. The apparatus 100 includes an effective dot generator 110, an effective dot clock calculator 120, and a storing unit 130. Referring to FIG. 1, the effective dot generator 110 receives a video clock signal (VCLK) and video data, and generates effective dots at a high level. The effective dot clock calculator 120 accumulates and counts the effective dots generated by the effective dot generator 110 in response to a printing synchronous signal. The effective dot clock calculator 120 multiplies the number of the accumulated effective dots by the volume of toner consumption per dot and outputs a total accumulated volume of toner consumption. The storing unit 130 stores the total accumulated volume of toner consumption calculated by the effective dot clock calculator 120.
This method of estimating the volume of toner consumption does not consider that the volume of toner consumption corresponding to overlapping areas between adjacent dots should be subtracted from the average volume of toner consumption per dot. Hence, the volume of toner consumption is inaccurately calculated.
Another method of calculating the volume of toner consumption is disclosed in European Patent Publication No. 0587172, the entire contents of which are incorporated herein by reference. In this method, the integral volume of toner consumption is calculated by detecting the number of consecutive dots and the number of the consecutive dots is multiplied by the volume of toner consumption per dot. Integral rates are adjusted according to the intensity of an image (i.e., an increase in the number of the consecutive dots changes the integral rate).
To solve the problems discussed above and others, the embodiments of the present invention provide a method and apparatus for accurately estimating the volume of toner consumption of an electrophotographic image forming device, such as a laser printer, by subtracting the volume of toner corresponding to overlapping areas between adjacent bits of video data sequentially input by the bit, from an average volume of toner consumption per bit.